March Moth

The March Moth (Alsophila aescularia) is a moth belonging to the family Geometridae within the order Lepidoptera. Known for its early emergence, it is a significant pest that can impact a variety of deciduous trees and shrubs throughout orchards and woodland areas in temperate climates.

This species primarily feeds on a broad spectrum of hosts, including essential fruit trees such as apples, pears, cherries, and plums. It is also frequently found on forest trees like lime, maple, and oak. When infestation levels are high, the larvae are capable of causing substantial defoliation across entire stands of trees.

The biology of the species is notable for its sexual dimorphism: adult females are flightless and must crawl up tree trunks to reach egg-laying sites. The eggs are typically deposited in clusters near buds during the late winter or early spring. Larvae emerge in spring to feed on tender foliage before descending to the soil to pupate in a subterranean cocoon.

The larvae are the destructive stage of this insect, causing damage by skeletonizing leaves or consuming them entirely. This loss of foliage reduces the tree's photosynthetic capacity, which directly stresses the plant, inhibits fruit development, and can lead to reduced vigor if defoliation occurs repeatedly over several years.

Effective management strategies include the use of grease bands or sticky traps on tree trunks to intercept the flightless females as they ascend. Cultural practices, such as maintaining bird populations that prey on larvae, are also beneficial. In cases of severe infestation, targeted applications of approved insecticides during the larval stage are recommended for optimal control.